SPECIES OF MAMMALS OF THE PACIFIC AREA 121 islands is even more remarkable than that of the bat (^Lasiurus) found there.
Jumping Mice and Their Allies. Family Zapodid^ The Striped Tree Mouse or Birch Mouse (Sicista), ranging from Norway and Hungary to eastern Siberia, is found on Sakhalin Island. It looks more like the true mice than its relatives the North American jumping mice. As in the latter, the cheek-teeth are four above, three below, and the forward opening from the bony eye-socket is large and rounded, rather than constricted and slit-like. The striped tree mouse is yellowish brown above, yellowish white below; a black stripe runs down the middle of the back from the crown to the tail. The total length is five and one-fourth to six inches, of which the tail is three to three and one-half inches. The striped mouse lives in open birch woods as a rule, and feeds on seeds. It sleeps through the winter in cold climates in a nest built in a hollow tree or protected place.
Old World Porcupines. Family Hystricid^ Although they are thought to be related to the American "quill-pigs," the porcupines of southern Europe, Africa, and Asia differ much from them. They do not climb trees, and they have hollow quills on the tail which are long and firmly attached to the skin and which rattle when they are alarmed. Porcupines are represented in the Greater Sunda Islands by three genera. The meat of all is good to eat and tastes somewhat like pork. Old World Porcupines {Hystrix) occur on the larger islands from Sumatra to Sumbawa (and possibly Flores). They are about twenty-seven inches in total length ; the tail occupies about five inches of this, excluding the quills. The animals weigh about eighteen pounds. The head and shoulders are covered with short spines but from the back and rump arise larger stouter quills, six or eight inches long, banded with black and white. Even longer, but thin flexible quills project beyond this
122 MAMMALS OF THE PACIFIC WORLD Fig. 50 — Asiatic Porcupine armor. A porcupine tries always to keep its rear directed at an enemy ; the quills are erected by strong skin muscles and the animal is said to run backward. For the most part porcupines are nocturnal and feed largely on roots and succulent vegetation.
Brush-tailed porcupines (Atherurus) have almost as wide a range as the common porcupine, but they are not found east of Sumatra. They look like large, blunt-nosed, spiny rats, with the relativity short tail ending in a tuft of hollow quills, each of which somewhat resembles a string of flat beads. The spiny quills that cover the body are grooved ; most of the stiff spines are about two inches in length, although some of the thin ones are three times as long. The brush-tailed porcupine is about thirty-two inches in total length, of which the tail is about onethird.
The Long-tailed Porcupine (Trichys) resembles its brushtailed relative, but its spines are shorter and the hairs of the long tail are parallel-sided. This rare porcupine is found only in Borneo and Sumatra.
SPECIES OF MAMMALS OF THE PACIFIC AREA 123 Fig. 51 — Brush-Tailed Porcupine Rabbits and Their Allies. Order Lagomorpha The rabbit family and the related group which contains the mouse-hares or pikas, resemble the rodents by having a large space between the incisors and the cheek-teeth and by having a single pair of lower and one functional pair of upper incisors. A second small pair of incisors is present behind the functional upper pair. The enamel is not confined to the front of the incisors, as in the rodents. The lower jaw moves from side to side in chewing, rather than back and forth, and there are also many internal differences between the rabbits and the true rodents. The members of the rabbit family are much alike ; they differ chiefly in size, length of ear, and precise pattern of the teeth. The tail varies in size and conspicuousness, but it is always visible. The pikas or mouse-hares have ears that project only slightly above the top of the head, and their hind feet and legs are not more elongated than those of squirrels ; the tail is not visible externally.
124 mammals of the pacific world Rabbits and Hares. Family Leporid^ The Arctic Hare (Lepus poadromus) is likely to be present on the landward Aleutians. This is a large hare, about two feet in total length, and heavily built. In winter the animals become white, excepting only the black-tipped ears, while in summer they are dull grayish brown, with white hind feet. The short ears measure about three and one-fourth inches from the notch. Arctic hares are larger as a rule than our snowshoe rabbits and the Eurasian varying hare. They differ little from those animals.
They form one of the principal foods of foxes, wolves, and great snowy owls in the regions where they are found. The seasonal change in color aids them to escape from their enemies ; their summer coat blends with the vegetation and their winter coat makes them almost invisible on the snow, so long as they stay still.
Eurasian Varying Hares (Lepus timidus) resemble American snowshoe rabbits. Their color is dull grayish brown in summer and white in winter excepting the tips of the ears. The head and body length is about twenty inches ; the ears measure about three and one-half inches from the crown of the head. This species ranges from Scotland and the Scandinavian Peninsula through Siberia to the northern Japanese Islands and the Kuriles.
The Japanese Hare (Lepus hrachyurus) occurs on the southern Japanese Islands. It has short ears — ^less than three inches long — and is a little smaller than our varying hare. Its color is dull brown, with the head, neck, belly, and limbs russet. The tail is scarcely longer than the hair of the rump ; it is brownish above and dull whitish below.
The Black-naped Hare {Lepus nigricollis) was introduced into Java from Ceylon or India. This species is dull brown, mixed with blackish on the sides and back, becoming paler on the feet. A band of blackish brown forms a collar around the
SPECIES OF MAMMALS OF THE PACIFIC AREA 125 neck, whence its name is derived. In size and proportions it is not very different from the American snowshoe rabbit. The Formosan Hare {Caprolagus formosus) is closely related to the harsh-furred hare of southern China. Its color is grayish drab, mixed with black, the tips of the hairs mostly buffy. Its dimensions nearly equal those of our cottontails, the tail being shorter but the other proportions similar. The Luchu Islands Rabbit (Pentalagus furnessi) has only five upper cheek-teeth, instead of the usual six in this family. Its color is very dark brownish black, with an admixture of buffy, becoming mahogany-colored on the rump ; the feet and tail are yellowish brown. The back has a jet-black stripe extending from the neck to the beginning of the mahogany color on the rump. The ears are proportionately short (less than two inches in length), but the body is about the size of the American snowshoe rabbit ; the hind feet are smaller. This rabbit, known only from a few specimens, is one of the rarest mammals in museum collections.
The Sumatran Hare (Nesolagus netscheri), of peculiarly striped appearance, is grayish yellow on the front parts, gradually becoming rich mahogany-brown on the haunches. A black stripe begins at the nose and runs the whole length of the animal ; it broadens between the ears, and on each side a black band runs forward from the back of the neck onto the cheeks. A black stripe extends back from the shoulders to join the dorsal stripe near the haunches and yet another black band comes up from the groins a little behind this. The outersides of the thighs are black, as is also a band around each hind foot. The fur is short and woolly and the ears are short — about one and onehalf inches in length. This rabbit is a little larger than the cottontails of the United States.
The European Rabbit {Oryctolagus)^ introduced into Australia in 1788, has since assumed the proportions of a first-class pest, having destroyed enormous acreages of grazing lands. Certain values have eventually emerged : rabbit fur is made into
126 MAMMALS OF THE PACIFIC WORLD felt hats or imitations of popular skins, and during World Wars millions of frozen carcasses are eaten as meat. PiKAS. Family Ochotonid^ The Pikas, Conies, or Mouse-hares are only half as large as cottontails. They have mouse-like ears but no visible tail. A single species (Ochotona hyperhorea) occurring on the large island of Hondo or Honshu, Japan, is found in rocky places, probably above the timber-line. Pikas have a peculiar call — a long ventriloquistic whistle or bleat. Piles of "hay" which they gather under the shelter of large stones are often the only signs of their presence.
Whales and Porpoises. Order Cetacea Whales and their smaller relatives are mammals that have become greatly modified for life in the water. Their forms are fish-like, rounded and tapering, without a constriction at the neck. The tail, broadened and flattened, is shaped into a propelling organ much like a fish's tail, but is horizontal instead of vertical. The front limbs are paddle-like, but no external trace of the hind limbs remains. The skin is hairless, smooth, and shining ; immediately under the surface lies a thick layer of fatty tissue or blubber. There is usually a median fin on the back. The eyes are small for the size of the head. There is no external ear, and in some cases the middle ear is completely separated by thick tissue from the exterior. The opening of the nostrils, through a paired or single "blowhole," is almost as far back as the eye or even behind it. These mammals will rarely be seen close enough to assure their identification. Some may be seen washed up on the beaches, and a few species live in the mouths of rivers or in harbors. Great gaps exist in our knowledge of these sea mammals, as they are too large for us to keep under observation in aquariums or for us to attach recording machines to them. The distribution of small species of little commercial value is still poorly known. Records of such whales
SPECIES OF MAMMALS OF THE PACIFIC AKEA 127 and porpoises, especially if accompanied by photographs and skulls, are very desirable.
Whalebone Whales. Suborder Mysticeti Whalebone whales have no teeth, although there are rudiments formed in the embryo. In the place of teeth the upper jaw has developed rows of horny, fringe-like whalebone which function as a sieve. The mouth opens wide and a great quantity of water is taken in. The mouth is then closed and the water forced out through the whalebone by the tongue, leaving the small fish and shrimp-like animals caught by the sieve to be swallowed.
The Pacific Right Whale {Euhalcena), both southern and northern species, has the body tapered gradually to the base of the tail. The head occupies about one-fourth of the total length, which is about fifty feet in adults. These whales have no throat grooves nor do they have a dorsal fin (compare with the finback whales).
The northern right whale is almost restricted to the waters north of the fortieth parallel, and although usually found far from shore, is taken off the coasts of Japan, Kamchatka, and the coast of Alaska.
The southern right whale is found largely between thirty and fifty degrees south latitude ; in the Pacific it has been taken in numbers off southern Australia, near New Zealand, and off the coast of Chile. Other records are rare.
The Bowhead or Greenland Right Whale {Balcena) is more massive than the other right whales. The head occupies about one-third of the total length, which in adults is from fifty to sixty feet. The head is thicker and more arched in dorsal profile than the northern and southern right whales, and the body tapers less regularly to the base of the tail. The bowhead is found in the Arctic Ocean and in the Bering and Okhotsk Seas, but it may range south of these last two regions in the winter. This species is now rare.
128 MAMMALS OF THE PACIFIC WORLD The Pygmy Right Whale {Neohalcena) is about twenty feet long, the head being about one-fourth of the total length. The color of the whalebone is pale yellow margined with black, while that of other right whales is usually black. The pygmy right whale is found in New Zealand and Australian waters and off South America.
The Gray Whale (Rhachianectes) , like the several foregoing species, lacks the dorsal fin, but the back shows a number of wave-like bumps, especially toward the tail. The head is small — less than one-fourth of the total length. The throat has two longitudinal folds, about six feet in extent, and the body is more slender than that of the right whales. The whalebone plates are only about fifteen inches in length. Adults are thirty-five to forty feet long. The gray whale, found chiefly near the coast, was once common along the Pacific coast of North America and in the Sea of Japan, but whaling has almost exterminated the species.
The Humpback Whale (Megaptera) frequents the coasts and bays of all the great oceans. Adults generally reach a length of about fifty feet. The body is thickset and clumsy in build. The fins are very long, about fourteen feet from base to tip in adults, and the front margin is irregularly wavy. The throat has a number of longitudinal folds, like those of the related finbacks. The humpback's blow or spout (the mixture of air and water spouted from the blowholes) is short and broad, rising almost vertically. The humpback is one of the few goodsized whales that can jump clear out of the water. Like most whalebone whales it feeds on small shrimps but eats a few fish as well.
Finback Whales or Rorquals (Balcenoptera, Sibbaldus) include the largest of all known animals, the blue whale or sulphurbottom. This species {Sibbaldus musculus) reaches a length of slightly over one hundred feet and a weight of more than one hundred tons. Its spout is more than fifteen feet high, and like that of most whalebone whales is almost vertical. Other kinds